Mulder and Scully investigate the death of a child who was killed following after a balloon that floated onto some railway tracks — moving against the wind.
- Adult Fear: Your child wandered off in a public place because he wandered off while you looked away for a while (going to the bathroom), even though you had tied him up. And then you see him get hit by a train.
- Badass Preacher: The Caluşari. Also a Badass Crew.
- Creepy Child: Charlie has his moments, but Michael is so much worse. That little actor was damn good.
- Death of a Child: Teddy was just a two-year old boy and he died during a teaser. His mother has lost another child before that.
- Enhance Button: Sort of, with the photo from the funfair. Pressing a few buttons and applying a few filters apparently produces proof of a ghostly presence.
- Evil Is Petty: When back in the Holvey house, Charlie purposefully needles his mother about the death of his brother Teddy.
- Evil Twin: Charlie's twin Michael died at birth, and is essentially haunting the living brother, killing people around them.
- Good All Along: Grandmother and the Caluşari.
- Hollywood Exorcism
- Ironic Name: Charlie's stillborn twin is named for the archangel that cast out Satan.
- Munchausen Syndrome: Scully initially suspects this is the case, with the grandmother being the perpetrator.
- Non-Nazi Swastika: Used by the Grandmother and the Caluşari.
- Ritual Magic
- Sequel Hook: While holding down Charlie, Mulder looks the snarling devil child straight in the eyes. He's warned by the Caluşari to be careful in the future, because the devil now knows him.
- Social Services Does Not Exist: Averted. Scully thinks they need to get Charlie away from his family (specifically his grandmother). Karen Kosseff, an FBI therapist who appears in several episodes, tries talking to Charlie.
- Spooky Photographs: A digitally enhanced photograph shows a blur leading the balloon that lures Teddy towards the train tracks. It's the "spectral snap" type of the trope.
- Ultimate Evil/Satan: Michael is implied to be Satan.